It looks like we put the thread in HN's second-chance pool (https://news.ycombinator.com/item?id=26998308), so it got re-upped and given a random slot on the frontpage.
The relativized timestamps are an artifact of the re-upping system. There are past explanations here: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que....
Sorry for the confusion! I know it's weird but the alternative turns out to be even more confusing and we've never figured out how to square that circle.